Why have so many men stopped working?

Richard Kessler (right) took time off to raise his son, Chris, and now he can't find a job.

Fifty years ago, nearly every single working-age American man had a job or was looking for one.

That's not the case anymore.

The labor force participation rate for men ages 25 to 54 stood at nearly 97% in 1965, but now hovers near a record low of 88%. That rate includes those who are working or have looked for a job in the past four weeks.

If the participation rate had held steady, more than five million additional men would be in the workforce.

Men are dropping out of the labor force in large part because they can't find positions that pay decently or they don't have the education and skills to land employment, experts say.

Richard Kessler is one of them.

Kessler, who worked as a research analyst and database manager at financial information firms, hasn't held a job since he was laid off during the recession of the early 1990s. He was 37.

Unable to find a job, he became a stay-at-home dad to his son, Chris. Still, he looked for work and went through a retraining program, learning computer skills such as Word and Excel,in the mid-1990s. The positions he was offered, however, paid only $8 an hour.

"It didn't make sense to give that to a babysitter," said Kessler, now 60, who lives in Bernardsville, N.J., with his wife, a business analyst.

Kessler decided to start looking again when Chris hit his teen years. But that coincided with the Great Recession, when jobs were againscarce. He hasn't sent out a resume in more than a year, saying he now lacks the technical skills and references needed to land employment.

"I don't know what's worse -- the stress of not having a job or the stress of having a job," he said. "I have a college degree. Now it's totally worthless."

Other men have different issues,most notably, criminal records. A growing number of men who should be working are in prison or have rap sheets that make it tough for them to get hired.

There were 5.6 million men in prison, on probation or on parole in 2013, according to the latest federal Bureau of Justice Statistics. About 34% of men age 25 to 54 without jobs have criminal records, according to a New York Times/CBS News/Kaiser Family Foundation poll from earlier this year.

Also, increasingly, men are opting to sign up for the Social Security Disability Insurance program, which exploded during the Great Recession. The number of disabled male workers doubled between 1993 and 2013 to 4.6 million, the latest figure available.

Dave Berkenbush would work if he could find a decent job.

Dave Berkenbush would work if given the chance, but he can't find a job that pays enough for him to cover his medical bills. Berkenbush, who has cystic fibrosis, has been on disability since he was let go from his last payroll accounting post in 2006.

Last year, he looked into temp jobs in his field, but they only paid $15 to $18 an hour, less than half what he was making 15 years earlier. That won't cover his medication, which costs close to $100,000 a year.

"It doesn't pay to pursue these jobs," said Berkenbush, 55, who lives in Pequannock, N.J., and recently had to dip into his retirement accounts for the first time.

Younger male workers, particularly those without college degrees, are also falling out of the labor force, said David Autor, economics professor at the Massachusetts Institute of Technology. With declines in the manufacturing and construction industries, there are fewer opportunities for these men to find gainful employment. So many work off the grid, sign up for government assistance or turn to a life of crime.

College educated or not, those with gaps in their resumes can find it tougher to land an interview, much less a job. Even a six-month break can raise questions.

"If you are not in the game for a certain amount of time, you become unemployable," said John Silvia, chief economist, Wells Fargo. "It's a downward spiral."

The declining participation rate isn't only a problem for the men who can't find jobs and their families. These men are not contributing to the economy or paying taxes.

And they are proving less attractive to women. Solid employment is the #1 priority women want in mate, according to a Pew Research Center report last year.

"Women are choosing not to marry men who won't be economic partners," Autor said.